The invention relates to electric motors, and more particularly, to the structure of an inside-out hysteresis synchronous motor.
Inside-out motors are characterized by a fixed shaft or stator, and an externally disposed rotating structure. Such motors are commonly used to provide motive power for rotating gyroscopic apparatus, and the like. One such motor is disclosed in a co-pending application, Ser. No. 370,641 entitled "Sensor Assembly for Strapped-Down Attitude and Heading Reference System" by B. F. Rider now U.S. Pat. No. 4,444,053, which is assigned to the same assignee as the instant invention. Synchronous motors operating in a varying thermal environment often exhibit unacceptable slip, i.e., the difference between synchronous and operating speeds, as ambient temperature changes. The thermal expansion loops in the motor structure must remain matched over temperature extremes in order to maintain the preload on the motor bearings.
It is, therefore, an object of the instant invention to provide an improved hysteresis synchronous motor having minimal slip.
It is another object of the present invention to provide an improved inside-out hysteresis synchronous motor having minimal slip while maintaining bearing preload over temperature extremes.